In recent years, a virtualization technology that operates virtual machines in physical servers is used. For example, in each corporation, an environment increases in which virtual machines are operated in physical servers by using virtualization software. Furthermore, in public cloud environments on the Internet or in private cloud environments in corporations, in order to efficiently use the computer resources, virtualization software is used as a basic element technology. When a physical server in which the virtualization software is running is in abnormal operations or indicates a sign of abnormality, the virtualization software has the function of moving a virtual machine running on a physical server to another physical server. This moving of a virtual machine is also referred to as “migration”.
Because logs of a virtual machine are stored in a running physical server, when a virtual machine moves across multiple physical servers, each of the logs is stored in the multiple in a distributed manner. Consequently, if some malfunction occurs in the virtual machine, an administrator that manages the virtual machine needs to check the distributed logs of the virtual machine in the multiple physical servers located at multiple locations by tracking back along the move history of the virtual machine.
Accordingly, there is a proposed technology that allows log files in physical servers to be referred to by providing links to log files that are stored, in a distributed manner, in the multiple physical servers and by clicking the links via a screen on a management terminal.
Furthermore, there is also a proposed technology that moves, when a virtual machine needs to be moved to another physical server, log information from a physical server at the move source, to a management server.
Patent Document 1: Japanese Laid-open Patent Publication No. 2010-277595
Patent Document 2: Japanese Laid-open Patent Publication No. 2011-8481
However, with the conventional technology, because the logs of the virtual machine are stored in multiple servers in a distributed manner, there may sometimes be a case in which a checking operation of the logs of the virtual machine becomes complicated.
For example, with the technology for providing a link to log files, when the location of a physical server in a network is changed or when the location of a log file stored in a physical server is changed, the log file is not able to be referred to. Furthermore, with the technology that provides a link to a log file, when a malfunction occurs in a virtual machine, if a physical server that was moved in the past is not present any more or if a physical server has failed, it is not able to check logs in the physical server by going back into the past.
Furthermore, with a technology that collects, when a virtual machine is moved to another physical server, log information into a management server, the log information is separately stored in a management server and a physical server in which a virtual machine is running.